Issue #3094047 by dww: @see links in ckeditor module point to deprecated version of docs

(cherry picked from commit ea29d982)

core/modules/ckeditor/js/ckeditor.stylescombo.admin.es6.js

@@ -92,7 +92,7 @@
         const element = classes.shift();
 
         // Build the data structure CKEditor's stylescombo plugin expects.
-        // @see http://docs.cksource.com/CKEditor_3.x/Developers_Guide/Styles
+        // @see https://ckeditor.com/docs/ckeditor4/latest/guide/dev_howtos_styles.html
         stylesSet.push({
           attributes: { class: classes.join(' ') },
           element,

core/modules/ckeditor/src/CKEditorPluginInterface.php

@@ -68,8 +68,8 @@ public function getLibraries(Editor $editor);
   /**
    * Returns the Drupal root-relative file path to the plugin JavaScript file.
    *
-   * Note: this does not use a Drupal library because this uses CKEditor's API,
-   * see http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.resourceManager.html#addExternal.
+   * Note: this does not use a Drupal library because this uses CKEditor's API.
+   * @see https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_resourceManager.html#method-addExternal
    *
    * @return string|false
    *   The Drupal root-relative path to the file, FALSE if an internal plugin.

core/modules/ckeditor/src/Plugin/CKEditorPlugin/StylesCombo.php

@@ -150,7 +150,7 @@ protected function generateStylesSetSetting($styles) {
       $element = array_shift($classes);
 
       // Build the data structure CKEditor's stylescombo plugin expects.
-      // @see http://docs.cksource.com/CKEditor_3.x/Developers_Guide/Styles
+      // @see https://ckeditor.com/docs/ckeditor4/latest/guide/dev_howtos_styles.html
       $configured_style = [
         'name' => trim($label),
         'element' => trim($element),